A novel therapeutic compound was found to induce bladder tumors in male rats. Given the location of the tumors and the increased amounts of calcium- and magnesium-containing solids found in the urine of treated animals, we hypothesized that tumorigenesis was secondary to urine crystal formation rather than a direct effect of the drug on urothelium. To investigate the basis for the response, a method of acidifying rodent urine was needed. This study tested the efficacy of 1% dietary NH 4C1 in reducing the urinary pH of male mice. After 1 wk, urinary pH (mean ± SD) at 1 h after light onset was 7.51 ± 0.32 among controls compared with 6.21 ± 0.31 for the NH 4Cl-fed group. After 2 wk of supplementation, urinary pH was 7.78 ± 0.41 for controls and 6.20 ± 0.30 for the NH 4Cl-fed group. To investigate whether the time of collection altered urinary pH, samples also were collected 8 h after the start of the light cycle on the day of the 2-wk collection. Urinary pH was 7.12 ± 0.28 for the control group and 5.80 ± 0.23 for the NH 4Cl-fed mice. The pH differences between control and NH 4Cl-fed groups and the differences in pH within groups at 1 and 8 h were statistically significant. Dietary NH 4C1 is an effective urinary acidifier for mice. When evaluating the pH of mouse urine, care should be taken to compare samples collected at the same time after the start of the light cycle.
|Original language||English (US)|
|Number of pages||3|
|Journal||Journal of the American Association for Laboratory Animal Science|
|State||Published - Mar 2009|
All Science Journal Classification (ASJC) codes
- Animal Science and Zoology